Abstract
Coenzyme Q(10) (CoQ(10)) has an important role as an antioxidant. Being that oxidative stress is one of the mechanisms involved in the pathogenesis of Parkinson's disease (PD) and other neurodegenerative diseases, several studies addressed the concentrations of CoQ(10) in the different tissues of patients with PD and other parkinsonian syndromes (PS), trying to elucidate their value as a marker of these diseases. Other studies addressed the potential therapeutic role of CoQ(10) in PD and PS. We underwent a systematic review and a meta-analysis of studies measuring tissue CoQ(10) concentrations which shows that, compared with controls, PD patients have decreased CoQ(10) levels in the cerebellar cortex, platelets, and lymphocytes, increased total and oxidized CoQ(10) levels in the cerebrospinal fluid and a non-significant trend toward decreased serum/plasma CoQ(10) levels. Patients with multiple system atrophy (MSA) showed decreased CoQ(10) levels in the cerebellar cortex, serum/plasma, cerebrospinal fluid, and skin fibroblasts. Patients with Lewy body dementia (LBD) showed decreased cerebellar cortex CoQ(10), and those with progressive supranuclear palsy (PSP) had decreased CoQ(10) levels in the cerebrospinal fluid. A previous meta-analysis of studies addressing the therapeutic effects of CoQ(10) in PD showed a lack of improvement in patients with early PD. Results of the treatment with CoQ(10) in PSP should be considered preliminary. The potential role of CoQ(10) therapy in the MSA and selected groups of PD patients deserves future studies.